A first type of alternative current (AC)/direct current (DC) power supply only provides half-wave rectification of a positive half cycle of an AC input voltage of the power supply. Alternatively, only half-wave rectification of a negative half cycle of the AC input voltage may also be performed. Consequently, the input energy corresponding to the non-rectified half cycle is lost.
Another type of AC/DC power supply provides full-wave rectification of both the positive half cycle and the negative half cycle of an AC input voltage of the power supply. For instance, the full-wave rectification is implemented by a diode bridge. The power efficiency of the power supply is improved, since it is capable of recovering the input energy corresponding to both rectified (positive and negative) half cycles. However, such power supplies usually have their AC input having an input zero volt reference, and their DC output having an output zero volt reference different from the input zero volt reference.
Therefore, there is a need for a common zero volt reference AC/DC power supply with positive and negative rectification, and a method of operation of the power supply.